So what do you get by joining your local or workplace credit union? We asked three unions in Derry, Telford and Glasgow. And we found big differences in rates paid to savers and charged on loans.

Across Ireland - north and south - around one in two adults are credit union (CU) members. The Waterside CU in Derry was set up in 1964 and now has 6,000 members.

"We have around 4,000 borrowers," says Waterside manager Uel Adair. "We charge the maximum 1% a month on outstanding loan balances or 12.46% a year but at the end of each year there is a rebate for borrowers. In 2004, it was 20% of the interest paid, the year before 15%."

Waterside CU, which is based in the local community, has assets of £10m, with around £5.7m lent to members. It has a £10,000 loan ceiling but the average loan is less than £1,000.

"If we didn't exist, many of our members would have to use door to door credit with APRs hitting 177%," he says.

Waterside's savers received a 3% dividend last year - the equivalent of interest.

All CU members have to save a regular sum but it can be as little as 50p a week.

The Fairshare CU in Telford, Shropshire, has around 3,500 members. All live or work in the Telford area. It was set up by Sally Hall, who worked for Telford Council's finance department.

"We have seven part-time workers," says Jean Cope. "You have to be a member for 10 weeks before you can borrow and there is a £2 one-off joining fee."

Fairshare expects members to save on a regular basis - many do so via payroll deduction as well as standing orders. A few save as much as £300 a month, but some as little as 50p a week.

Fairshare has not fared as well financially over the past years as Waterside. "Recent Financial Services Authority regulations such as building up reserves against bad debts have hit dividends. Last year, we paid savers 0.5% but we hope to build that up to 1.5% this year," Jean says.

Fairtrade's big attraction is the 12.46% APR. A £1,000 borrower over a year pays £88.86 a month - £66.32 interest over the period.

Defaulters can expect to be chased. "We monitor bad debts, and send out two letters before calling in debt collectors," Jean adds.

The Glasgow Council CU is the UK's largest with 18,000 members, £47m in assets and 22 full-time staff. It has lent £37m to 12,000 borrowers.

"We started in 1989," says manager Jean Nightingale. "Many council employees are low paid so without us, they would end up with door-to-door lenders."

It has lower interest rates than many other unions. Unsecured loan rates depend on how much is borrowed, not on credit checks.

Interest on a loan of more than £10,000 is 7.9%, moving up to 11% for small sums. This CU is one of the few to offer mortgages - mainly for right-to-buy properties. It charges 6% with a maximum 25-year repayment period.

The typical saver puts in £40 to £50 a month on top of loan repayments. Last year, savers received a 4% dividend; there are hopes of beating that this year.